The present invention relates to cutting metal-working machines and, more specifically, to a cutter holder for a cutting metal-working machine.
Regular cutting metal-working machines such as lathes, power drills, and etc., commonly have a cutter holder or chuck assembly adapted to hold the cutter in position, enabling the cutter to be rotated with the transmission shaft. A conventional cutter holder or chuck assembly for this purpose comprises a body, the body having a plurality of oblique slots provided around the periphery, a plurality of pawls respectively slidably mounted in the oblique slots of the body, and a driving ring controlled to move the pawls radially forwards/backwards to lock/release the cutter. This structure of cutter holder or chuck assembly cannot be used in a cutting metal-working machine that needs to rotate the cutter in the reversed direction, because it releases the chuck when rotated in the reversed direction.
The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a cutter holder for cutting-metal working machine, which enables the cutter to be rotated with the transmission shaft of the cutting metal-working machine clockwise as well as counter-clockwise. It is another object of the present invention to provide a cutter holder for cutting metal-working machine, which imparts a positive clamping force to hold down the cutter for working. To achieve these and other objects of the present invention, the cutter holder cutter holder comprises a coupling shaft, a driving shaft inserted into the coupling shaft, the driving shaft having toothed rails respectively engaged into corresponding radial slots of the coupling shaft, a driving nut mounted on the coupling shaft and meshed with the toothed rails of the driving shaft for enabling the driving shaft to be moved axially upon rotary motion of the driving nut; a retainer ring mounted on the coupling shaft and disposed in contact with the driving nut at one side, the retainer ring having a plurality of spring leaves radially arranged around the periphery thereof, a driving ring mounted around the coupling shaft and press-fitted onto the driving nut, the driving ring having retaining grooves for the positioning of the spring leaves of the retainer ring, and a chuck fastened to one end of the coupling shaft and adapted to hold down a cutter.